1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming system.
2. Description of the Related Art
In a conventional developing method using mono-component toner, there is a contact developing method which employs a developing roller, i.e., a developer bearing member, having an elastic layer. A toner regulating member, i.e., a developer regulating member, is brought into contact with the developing roller, so that a layer of the developer attached to the developing roller is regulated and friction-charged. The toner regulating member is a blade-shaped member which is a sheet metal supported at one end, and the underside of the other end makes contact with the developing roller. The developer which is coated on the developer roller by the toner regulating member develops an electrostatic latent image formed on a photosensitive drum using a potential of a bias applied on the developing roller.
Further, Japanese Patent Application Laid-Open No. 2006-163118 discusses applying a voltage between the developing roller and the toner regulating member. This is to stabilize a charge amount and a layer thickness of the coating layer of the developer formed on the developing roller.
However, since the voltage is applied between the developing roller and the toner regulating member, the toner is pressed against the developing roller while passing through the toner regulating member. As a result, the toner receives stress by the applied voltage, so that the chargeability of the toner is reduced and the cohesiveness of the toner is increased. Therefore, it becomes difficult to acquire an image which is stable for a long term.